Two-piece shield

ABSTRACT

Two similar, resilient tapered shield members, one slightly smaller than the other, each having a slit completely severing the member along one side, are placed around a cylinder or rod extending from the cavity to be protected, by opening each shield member along the side slit in order to admit the shaft or rod to a hole located in the smaller end of each shield member. The shield members are positioned with respect to each other so that the surface of each member completely underlies or covers the slit in the member above or below it, with the larger member substantially enclosing the smaller member. Means are provided for preventing the positioning of the shield members such that the slit of one shield member would directly overlie the slit of the other shield member, and for attaching the shield member to the opening of the protected vessel or cavity.

United States Patent Smith [111 3,856,314 1 Dec. 24, 1974 1 TWO-PIECE SHIELD [75] Inventor: Ernest L. Smith, Kansas City, Mo. [73] Assignee: Phillips Petroleum Company,

Bartlesville, Okla.

[22] Filed: Sept. 7, 1973 [21] Appl. No.: 395,031

[52] US. Cl. 277/1, 277/212 C [51] Int. Cl. F16j 15/32 [58] Field of Search 277/1, 212, 212 C, 124; 123/188 P; 259/125 [56] References Cited UNITED STATES PATENTS 2,858,118 10/1958 Perkins 2 59/l25 3,038,347 6/1962 Sloan et al.... 277/212 3,330,569 7/1967 Skinner..' 277/212 3,393,021 7/1968 Guth 277/212 3,601,420 8/1971 Binford.; .l 277/212 C Primary Examiner-Louis R. Prince Assistant Examiner-Robert 1. Smith Attorney, Agent, or Firm-Quigg & Oberlin [5 7] ABSTRACT spect to each other so that the surface of each member completely underlies or covers the slit in the member above or below it, with the larger member substantially enclosing the smaller member. Means are provided for preventing the positioning of the shield members such that the slit of one shield member would directly overlie the slit of the other shield member, and for attaching the shield member to the opening of the protected vessel or cavity.

11 Claims, 7 Drawing Figures PATENTEU DEC 4 m4 SHEET 1 BE 4 FIG. 7

FIG. 2

FATENTED UEE24 I974 I isumzu q FIG. 4

FATENTED 95324197? SHZET 3 0f FIG. .5

FIG. 6

sum u 115 g TWO-PIECE SHIELD other aspect it relates to a dust or drip cover Capable of admitting a shaft to the covered area. ln another aspect the invention relates to a method for installing a dust cover around a cylindrical shaft.

In the handling associated with the processing and packaging of many products, it is often necessary or desirable to exert a stirring, pumping, or similar force inside a vessel containing the product by means of a turning or reciprocating shaft. In such instances, it is desirable that the point at which the shaft enters the product-containing area be sealed as well as possible against the entrance of foreign material. Conventional dust and drip shields ordinarily comprise a solid, discshaped or frustoconical member through which the shaft can be inserted during assembly of the machine.

Maintaining a product free of foreign material is especially important in the handling of food products.'

Accordingly, an object of the present invention is to provide an improved dust or drip cover. Another object of the invention is to provide an improved dust or drip cover through which a shaft canextend. Another object of the invention is to provide a dust cover which is easily applied to 'or removed from a cylindrical opening through which a cylindrical shaft extends. Yet another object of the invention is to provide an improved method for applying a dust cover to an opening through which a cylindrical shaft extends. Other objects and advantages of the invention will be apparent from the following description of the invention and the appended claims. i

In accordance with the invention two resilient tapered shield parts are utilized, each having an opening at its narrow end through which a shaft can pass, an open large end, and a slit from the small end to the large end completely severing the side of each part. Each shield part can be placed around a shaft by spreading each part along the slit a sufficient width to accommodate the shaft into the center opening. The parts are then positioned so that the slits are not aligned and the surface of each part covers the area left exposed by the slit in the other. One cover part is slightly larger than the other and the parts are positioned on the shaft so that the smaller one can be telescoped inside the larger one to provide a more effective seal. A flange at the larger end of the larger part is then engaged around the opening to be protected so that the base of the inside part is held tightly against the top edge of the protected opening. The shield can be easily and quickly removed without the use of any tools and can be replaced after cleaning by placing both parts over the shaft and snapping them back into place.

is presently preferred that both keys l7 and 27 have Proper alignment of the slits in the two pieces can be assured by the-use of appropriately sized detents in the surface of each segment positioned so that the detents will mate when the shields are presented in the desired position with respect to each other.

In the drawings,

FIG. 1 is a plan view of'the smaller shield member.

FIG. 2 is an elevational cross section along line 2-2 of FIG. '1.

FIG. 3 is a plan view of the larger shield member.

FIG. 4 is an elevational cross section taken along line 4-4 of FIG. 3.-

FIG. 5 is an elevationalview in partial cross-section of the assembled shield in place on a filling machine.

FIG. 6 is a partial plan view in cross-section taken along line 66 of FIG. 5.

FIG. 7 is an elevational cross section along line 7-7 of FIG. 6.

Referring now to FIGS. v1 and 2, the smaller shield member 11 has a frustoconical main body 12. The partially closed smaller end of the frustoconical body '12 is formed by an annular flange 13 extending inwardly in a generally horizontal direction with a center opening 14 sized to provide a close fit with the shaft around which shield member 11 is to be used. An annular section 19 extends generally horizontally outwardly from the open large end of frustoconical body 12. An annular flange 15 extends downwardly in a substantially vertical direction from the outerperiphery of annular section 19. A slot 16 extends in an at. least generally, straight line from center opening 14 through annular flange 13, frustoconical main body 12, section 19, and annular flange 15 of shield memberll. Although the formation of slit 16 in a vertical plane is presently preferred, slit 16 can be formed at an angle to the vertical so long as the shield member 11 can be opened along the slit 16 to admit the shaft. Raised alignment key 17 extends outwardly from frustoconical body 12 and upwardly from annular section 19 to form an outwardly directed projection on the outer surface of shield member 11.

Referring now to FIGS. 3 and 4, the larger shield member 21 has a frustoconical main body 22. The partially closed smaller end of the frustoconical body 22 is formed by annular flange 23 extending generally horizontally inwardly from the upper end of frustoconical body 22 and having a center opening 24 sized to provide a close fit with the shaft around which shield member 21 is to be used. Opening 24 will ordinarily be the same nominal size as opening 14 of shield member 11. An annular section 29 extends generally horizontally outwardly from the open large end of frustoconical body 22. An annular flange 25 extends downwardly in alignment key 27 extends outwardly from frustoconical v body 22 and upwardly from annular section 29 to form an outwardly directed, inwardly opening pocket in the inner surface of shield member 21 corresponding in shape and location but being slightly larger than the key 17 on the smaller shield member 11. While keys 17 and 27 can be formed in any desired configuration, it

mating configurations with mutually engaging side surfaces extending at least generally vertically as illustrated in the drawings to provide maximum effectiveness of the locking of the shield members 11 and 21. While a single key 17 in the smaller shield member 11 and a single key 27 in the larger shield member 21 have been illustrated, any suitable number of keys can be employed. While the number of pocket keys has to be at least equal to the number of projection keys, there can be a larger number of pocket keys permitting more than one alignment so long as none of the permitted alignments allow overlapping of slot 16 and slot 26. Ridges 28 extending inwardly along the inside of bottom of flange 25 are adapted to engage shield member 21 with the opening to be covered in a snap-on arrangement. Ridges 28 can be in the form of separate ridges as illustrated or in the form of an annulargroove extending the entire circumference of flange 25.

Shield 21 is enough larger than shield 11 to permit shield 11 to nest inside shield 21 with the raised portion of alignment key 17 on the upper surface of shield 11, mating with the pocket of alignment key 27 in the lower surface of shield 21. Shield members 11 and 21 can be constructed from any resilient material suitable for the purpose and by any method known to the art. Shield members thermoformed from high density polyethylene have been found to work very well. Thermoforming the shield members is advantageous in requiring a minimum amount of material and providing conformity between the outer surface of the inner shield member 11 and the inner surface of the outer shield member 21.

Slots 16 and 26 can be of any desired width and the sides thereof can be either parallel or diverging by extending radially from the central axis of the shield member as long as at least one half of each shield member is entirely intact with sufficient overlap to contain the alignment keys l7 and 27. Wide slots permit easier application of shield members to a shaft, but narrow slots, such as those illustrated in the drawing, permit more effective shielding of an opening by increasing the overlap of the shield members. Slots narrower than openings 14 and 24 and having parallel sides are preferred for their ability to positively engage around a shaft and for their increased overlap. When the resiliency and flexibility of the material from which the shield members are produced permits, even narrower slots, such as those illustrated by the drawing, are especially preferred.

To engage shield members 11 or 21 around a cylindrical shaft the shield member 11 or 21 can be grasped by hand on each side of slots 16 or 26 and, by manually exerting upward pressure on one side of the slot and downward pressure on the other side as well as slight spreading pressure on the slot, can be sprung open a distance sufficient to admit a shaft the size of openings 14 and 24. When the spreading pressure is released, the resiliency of the member 11 or 21 causes the member to resume its original shape, thereby affixing itself around the shaft until it is removed by' spreading the shield members open and reversing the application process. Both application and removal of the shield members can be accomplished without access to either end of the, shaft.

FIG. illustrates the use of a shield employing shield members 11 and 21 in conjunction with a liquid filling machine 31 having a cylindrical housing 30 for a hollow cylindrical chamber 32 containing a pumping plunger 33 driven through cylindrical rod 34 by lever arm 35. A flange 37 is attached to rod 34. Flange 37 has a frustoconical configuration with the larger diameter at the bottom thereof being greater than the minimum diameter of the frustoconical body 22 of the upper shield member so that any condensate which might form on elements above flange 37 will fall on the downwardly sloping section 22 of the upper shield member 21, thereby minimizing the possibility of such condensate flowing along shaft 34 through openings 24 and 14. Arm 35 drives rod 34, flange 37, and pumping plunger 33 in a vertical reciprocating manner. The mechanism is illustrated in its extreme downward position.

In operation filling device 31 draws liquid into cylinder 32 through inlet/outlet 38 as pumping plunger 33, forming a tight seal with the wall of cylinder 32 by means of O-ring 39, is drawn upwardly in the cylinder by rod 34 and lever arm 35. When the cylinder is filled to a measured level, downward pressure is exerted on rod 34 by arm 35, causing pumping plunger 33 to expel the liquid through inlet/outlet 38. Valve means (not shown) associated with inlet/outlet 38 provides for communication of inlet/outlet 38 with a liquid supply source during the upward stroke of pumping plunger 33 and with the container to be filled during the downward stroke of pumping plunger 33.

The outside diameter of the large end of the smaller shield member 11 is such that the shield member 11 rests upon the top surface of cylinder housing 30, while the inside diameter of the large end of the larger shield member is sufficiently larger for flange 25 to slip downwardly over the upper portion of cylindrical housing 30. If desired, the upper portion of cylindrical housing 30 can be provided with an annular flange 41 extending outwardly from the outer surface thereon, and located so that ridges 28 on the bottom edge of flange 25 on outer shield member 21 can be snapped over flange 41, thereby rigidly engaging shield members 11 and 21 to cover the opening in cylindrical housing 30. In the absence of flange 41, ridges 28 can provide a friction fit against the exterior surface of housing 30.

FIG. 6 illustrates the relative positions of shield member 11, shield member 21, and shaft 34 as from above. Smaller shield member 11 is completely covered by larger shield member 21 except for the part exposed beneath slot 26. A preferred rotational relationship between slot 26 and slot 16 in the covered first shield member 11 is illustrated. Any angular relationship between the rotational positions of the two slots is acceptable as long as the surface of one member underlays or covers the slot in the other. An angular relationship between the two slots in the range of from about to about 270 is preferred, with an angular relationship in the range of from about to about 240 being more preferred.

FIG. 7 is an elevational cross section view of the shield members 21 and 22 in place around shaft 34 and engaged with the top of cylindrical housing 30. The

mating relationship between shield members 11 and 21' can be seen as frustoconical main body members 12 and 22, bottom flanges 15 and 25, and key ridges 17 and 27 fit closely together. Ridge 28 engaged over flange 41 maintains second shield member 21 in position over cylindrical housing 30, and the smaller shield member 11 is maintained in position on the top of cy-- ber 21.

Any suitable means can be used to maintain shield member 11 in the desired rotational juxtaposition to shield member 21. Although a preferred method using mating detents has been illustrated, mating radial ridges on the inside of shield member 21 and the outside of shield member 11, other various mating means, a roughened surface on one or both shield members, or similar methods can be used.

As is apparent from the foregoing description, this invention can readily be modified to, for example, use two frustopyramidal shield members to cover an opening having a square, rectangular, triangular or other cross section. Likewise, the openings at the small ends of the shield members can be fitted to the shape of a reciprocating shaft having a square, rectangular, triangular or other cross section or can be fitted to cover as close as is practical to a rotating shaft having a noncircular cross section.

Any suitable resilient material can be utilized in the manufacture of the invention and any known method of manufacture capable of producing a product having the desired shape can be used. Examples of materials which can be used are metals, fiberglass, plastics, and similar materials. Preferred materials include synthetic polymeric materials such as polyethylene, polypropylene, polystyrene, nylon, poly(vinyl chloride) and similar polymers. Especially preferred is high density polyethylene. Methods of forming plastic shield ports include injection molding, thermoforming, blow molding, compression molding and similar plastic manufacture techniques. A preferred method of manufacture is thermoforming from a sheet of synthetic organic thermoplastic polymeric material.

Reasonable variations and modifications are possible within the scope'of the foregoing disclosure and the appended claims to the invention.

What is claimed is:

l. A shield suitable for covering the opening between a movable shaft and a surrounding housing, said shield comprising a first resilient tapered shield member having a first opening at the narrow end thereof through which said shaft can pass, first annular means around its open large end adapted to contact the top surface of said housing, and a first slot extending from said first opening through said first annular means to said openlarge end to permit said first shield member to be engaged around said shaft without access to either end of said shaft; and second resilient tapered shield member having a second opening at the narrow end thereof through which said shaft can pass, second annular means around its open large end adapted to contact the outside surface of said housing, and a second slot extending from said second opening through said second annular means to said open large end of said second shield member to permit said second shield member to be engaged around said shaft without access to either end of said shaft, said second shield member being adapted to engage said first shield member along the outside surface of said first shield member and the inside surface of said second shield member with the slot in said first shield member being covered by the solid surface of said second shield member and the solid surface of said first shield member underlying the slot inber, with said first shield member inside, to said hous- 7 4. A shield in accordance with claim 3 wherein said slot in said first shield member and said slot in said second shield member are narrower than the diameter of said shaft, said slot in said first shield member and said slot in said second shield member forming an angle of from about to about 270 with each other, and wherein said first and second shield members are sufficiently resilient to permit said slots to be temporarily widened to engage said first and second shield members around said shaft.

5. A shield in accordance with claim 4 wherein said alignment means comprises at least one raised area on the outside surface of said first shield member in cooperation with at least as many raised areas on the inside surface of said second shield member adapted to engage said at least one raised area on the outside surface of said first shield member.

6. A shield in accordance with claim 5 wherein said engaging means comprises one or more lateral ridges on the inside circumference of said annular means of said second shield member, said one or more ridges being adapted to engage the outside surface of said housing. v 1

7. A shield in accordance with claim 6 wherein-said first shield member comprises a, frustoconical main body having a first annular flange at the narrow end thereof, said first flange extending inwardly in a generally horizontal direction and having an opening through which said shaft can pass, a second annular flange at the large end thereof extending outwardly in a generally horizontal direction and a third annular flange extending downwardly in a generally vertical direction from the outer periphery of said second flange; and

wherein said second shield member comprises a frustoconical main body having a fourth annular flange at the narrow end thereof, said fourth flange extending inwardly in a generally horizontal direction and having an opening through which said shaft can pass, a fifth annular flange at the large end thereof extending outwardly in a generally horizontal direction and a sixth annular flange extending downwardly in a generally vertical direction from the outer periphery of said fifth flange.

8. A shield in accordance with claim 7 wherein said alignment means comprises a key extending upwardly from the upper surface of said second flange and outwardly from said frustoconical main body of said first shield member, capable of mating with a pocket extending upwardly from the lower surface of said fifth flange and outwardly from said frustoconical main body of said second shield member.

9. A shield in accordance with claim 8 wherein said first and second shield members are thermoformed from a sheet of synthetic organic thermoplastic polymeric material.

7 8 10. A method for applying a shield between a shaft opening formed by said second slot to said second and a housing into which said shaft extends, said center opening. method Comprising positioning said second shield member with respect engaging a first resilient, Shield member having a to said first shield member in order to mate said shlen end with a first eehter opening through which first and second alignment means and enclose said sald shaft can h a large a first Slot first shield means within said second shield means; tend ng from said center opening through the edge and of Sald large open end of Saw] first Sheld member attaching said large open end of said second shield and first alignment means on the outer surface of said first shield member, around said shaft by pass- 10 ing said shaft through the opening formed by said slot into said center opening;

engaging a second resilient, shield member having a small end with a second center opening through member over the end of said housing.

11. A method in accordance with claim 10 wherein engaging said first shield member and said second shield member around said shaft is accomplished by grasping each respective shield member on either side which said shaft can pass, a large Open end, a of said respective slot, exerting upward pressure on one end Slot extending f said center opening side of the slot and exerting downward pressure on the through the edge of said large open end of said secethel: side of the Slot, Passing Said Shaft through the 0nd shield member, and second alignment means p g formed y 531d Slot, and releasing the Pressure on the inner surface of said se d shi ld member exerted on said respective shield member to permit said capable of mating with said first alignment means, respective shield member to resume its original shape. around said shaft by passing said shaft through the 

1. A shield suitable for covering the opening between a movable shaft and a surrounding housing, said shield comprising a first resilient tapered shield member having a first opening at the narrow end thereof through which said shaft can pass, first annular means around its open large end adapted to contact the top surface of said housing, and a first slot extending from said first opening through said first annular means to said open large end to permit said first shield member to be engaged around said shaft without access to either end of said shaft; and a second resilient tapered shield member having a second opening at the narrow end thereof through which said shaft can pass, second annular means around its open large end adapted to contact the outside surface of said housing, and a second slot extending from said second opening through said second annular means to said open large end of said second shield member to permit said second shield member to be engaged around said shaft without access to either end of said shaft, said second shield member being adapted to engage said first shield member along the outside surface of said first shield member and the inside surface of said second shield member with the slot in said first shield member being covered by the solid surface of said second shield member and the solid surface of said first shield member underlying the slot in said second shield member.
 2. A shield in accordance with claim 1 additionally comprising alignment means adapted to maintain said first member and said second member in a fixed juxtaposition.
 3. A shield in accordance with claim 2 additionally comprising engaging means located at the large diameter end of said second shield member, said engaging means being adapted to affix said second shield member, with said first shield member inside, to said housing.
 4. A shield in accordance with claim 3 wherein said slot in said first shield member and said slot in said second shield member are narrower than the diameter of said shaft, said slot in said first shield member and said slot in said second shield member forming an angle of from about 90* to about 270* with each other, and wherein said first and second shield members are sufficiently resilient to permit said slots to be temporarily widened to engage said first and second shield members around said shaft.
 5. A shield in accordance with claim 4 wherein said alignment means comprises at least one raised area on the outside surface of said first shield member in cooperation with at least as many raised areas on the inside surface of said second shield member adapted to engage said at least one raised area on the outside surface of said first shield member.
 6. A shield in accordance with claim 5 wherein said engaging means comprises one or more lateral ridges on the inside circumference of said annular Means of said second shield member, said one or more ridges being adapted to engage the outside surface of said housing.
 7. A shield in accordance with claim 6 wherein said first shield member comprises a frustoconical main body having a first annular flange at the narrow end thereof, said first flange extending inwardly in a generally horizontal direction and having an opening through which said shaft can pass, a second annular flange at the large end thereof extending outwardly in a generally horizontal direction and a third annular flange extending downwardly in a generally vertical direction from the outer periphery of said second flange; and wherein said second shield member comprises a frustoconical main body having a fourth annular flange at the narrow end thereof, said fourth flange extending inwardly in a generally horizontal direction and having an opening through which said shaft can pass, a fifth annular flange at the large end thereof extending outwardly in a generally horizontal direction and a sixth annular flange extending downwardly in a generally vertical direction from the outer periphery of said fifth flange.
 8. A shield in accordance with claim 7 wherein said alignment means comprises a key extending upwardly from the upper surface of said second flange and outwardly from said frustoconical main body of said first shield member, capable of mating with a pocket extending upwardly from the lower surface of said fifth flange and outwardly from said frustoconical main body of said second shield member.
 9. A shield in accordance with claim 8 wherein said first and second shield members are thermoformed from a sheet of synthetic organic thermoplastic polymeric material.
 10. A method for applying a shield between a shaft and a housing into which said shaft extends, said method comprising engaging a first resilient, shield member having a small end with a first center opening through which said shaft can pass, a large open end, a first slot extending from said center opening through the edge of said large open end of said first shield member, and first alignment means on the outer surface of said first shield member, around said shaft by passing said shaft through the opening formed by said slot into said center opening; engaging a second resilient, shield member having a small end with a second center opening through which said shaft can pass, a large open end, a second slot extending from said center opening through the edge of said large open end of said second shield member, and second alignment means on the inner surface of said second shield member capable of mating with said first alignment means, around said shaft by passing said shaft through the opening formed by said second slot to said second center opening. positioning said second shield member with respect to said first shield member in order to mate said first and second alignment means and enclose said first shield means within said second shield means; and attaching said large open end of said second shield member over the end of said housing.
 11. A method in accordance with claim 10 wherein engaging said first shield member and said second shield member around said shaft is accomplished by grasping each respective shield member on either side of said respective slot, exerting upward pressure on one side of the slot and exerting downward pressure on the other side of the slot, passing said shaft through the opening formed by said slot, and releasing the pressure exerted on said respective shield member to permit said respective shield member to resume its original shape. 